Antioxidants for Synthetic Lubricants and Methods of Manufacture

ABSTRACT

Provided are compounds of formula 
     
       
         
         
             
             
         
       
     
     wherein R 1  is t-octyl, AR is phenyl, R 2  is an alkyl substituted carboxyl and m is 0, 1, or 2. Lubricating oils and hydraulic fluids comprising a polyol ester lubricant in combination with one or more compounds of formula I and methods for their use are also provided.

CROSS REFERENCE TO RELATED APPLICATION

This application claims continuation priority to U.S. patent applicationSer. No. 11/672,559 filed on Feb. 8, 2007, the disclosure of which ishereby incorporated by reference in its entirety.

FIELD

The present invention is generally related to antioxidants forlubricants and more particularly to an antioxidant for syntheticlubricants such as polyol ester lubricants.

BACKGROUND

Synthetic lubricants are generally specified in demanding high valueapplications such as stationary turbines, jet engines, hydraulicsystems, and the like. Some synthetic lubricants are known as “polyolesters” and include compounds formed from monobasic fatty acids andpolyhydric alcohols having a “neopentyl” structure. Representativealcohols useful for forming synthetic ester lubricants include neopentylglycol, trimethylolpropane, pentaerythritol and dipentaerythritol. Thesealcohols are reacted to form esters with fatty acids generally havingfrom about five to about twelve carbon atoms including: valeric,isopentanoic, hexanoic, heptanoic, octanoic, isooctanoic,2-ethylhexanoic, pelargonic, isononanoic, decanoic and dodecanoic. Thealcohols listed above generally have no beta-hydrogens and differprimarily in the number of hydroxyl groups available to form esters.

Depending on the fatty acids selected, i.e., same or different andnumbers of carbon atoms, the properties of the polyol ester formed canbe “designed” to provide a particular viscosity range, pour point, flashpoint and volatility as required for particular applications. Lowermolecular weight acids, e.g., valeric, isopentanoic, etc., generally areused when flowability at low temperatures is important. Properties suchas oxidative stability and resistance to hydrolysis may be enhanced byincorporation of acids having branching. In many applications, mixturesof both higher and lower molecular weight acids provide desirableproperties. U.S. Pat. No. 4,440,657 discloses many simple esters,diesters and polyol esters suitable for use as lubricants.

In addition to selecting a synthetic lubricant based on its chemicalstructure, various additives are blended into the lubricant to enhanceits oxidation resistance, disperse sludge formed, improve hydrolysisresistance, passivate metals, inhibit rust and the like. Antioxidantsformed from polymerizing, for example, alkylated diphenyl amines andalkylated phenyl-α-naphthyl amines are widely used in many industrialapplications including, but not limited to, thermoplastic resins,lubricants and hydraulic fluids to improve resistance to oxidation. U.S.Pat. No. 3,509,214 discloses that aromatic secondary naphthyl amines orN-arylnaphthylamines may be coupled or cross-coupled to form oligomerswhich, when present as additives in synthetic lubricants, enhance theresistance of the lubricants to high temperature oxidation.

Additional representative antioxidant additives are disclosed in U.S.Pat. No. 5,160,647 which discloses formaldehyde condensation products ofalkylphenyl substituted-1-aminonaphthalenes. In this patent, all of thepreparations of the disclosed compounds are prepared in solvent with thecompound being isolated and purified as a solid material.

U.S. Pat. No. 3,492,233 discloses lubricant compositions containingdehydrocondensation products produced by chemically attaching anadditive molecule such as an antioxidant, load-carrying agent,detergent, anticorrosion agent and the like to a lubricant molecule byheating the additive and an organic lubricant base fluid in the presenceof an organic peroxide.

U.S. Pat. No. 6,426,324 discloses an antioxidant composition suitablefor ester fluid lubricants formed from diphenylamines and N-arylnaphthylamines in the presence of an organic peroxide. In thisdisclosure, a reaction with a polyol ester lubricant base is disclosed,but is, according to the disclosure, a byproduct and ways to minimizethe reaction between the amines and the polyol ester fluid arepreferred.

Present preparations of antioxidants for lubricant fluids are multi-stepand often require difficult and expensive separations and purifications.These current preparations add to the cost of preparing alreadyexpensive synthetic lubricants, such as polyol esters. If a compoundhaving suitable antioxidant properties were available and a lesscomplex, more efficient method for its preparation and incorporationinto synthetic lubricants was provided, the art of stabilized polyolester lubricants would be enhanced. Such a compound and a method for itspreparation and incorporation into a synthetic polyol ester lubricantare provided herein below.

SUMMARY

An embodiment of the invention includes a compound of formula

-   -   wherein R¹ is H or a linear or branched alkyl;    -   AR is phenyl, naphthyl, or phenanthryl;    -   in one embodiment, m=0; in another embodiment, m=1; and    -   in a further embodiment, m=2; and    -   R² is an alkyl substituted carboxyl.

Compounds of formula I are useful as antioxidant additives in syntheticlubricants, for example, polyol ester lubricants or hydraulic fluids.

In one aspect of the present invention, antioxidant additives aregenerally prepared by a condensation reaction of an alkylatedphenyl-α-naphthyl amine (ALK PANA) with formaldehyde in the presence ofa base lubricant. In one embodiment, a method of preparation includesmixing an alkylated phenyl-α-naphthyl amine, formaldehyde, glacialacetic acid, and a base lubricant, for example, a polyol ester. Thismixture is then heated and stirred to cause a condensation reaction.Water is generated and distilled off. Following the removal of thewater, the solution is heated and vacuum stripped to substantiallyremove residual water and acetic acid. The condensation reactionproduct, namely, an antioxidant, remains in the base lubricant.

The antioxidant and base lubricant mixture is then blended into the sameor a compatible lubricant. Additional additives or additive packages areadded as desired. Methods of the present invention that produceantioxidants from a condensation reaction of an alkylatedphenyl-α-naphthyl amine with formaldehyde in the presence of syntheticlubricants, such as polyol ester lubricants, without additionalisolation or work-up steps, greatly improve the efficiency of preparingthese high value lubricants with an antioxidant additive. Previously,preparation of these types of antioxidant compounds required multiplesteps to isolate and purify these types of compounds from the solventsin which they were synthesized.

DETAILED DESCRIPTION

An embodiment of the invention is a compound of formula

wherein R¹ is H, or a linear or branched alkyl; AR is phenyl, naphthyl,or phenanthryl; in one embodiment, m is 0; in another embodiment, m is1; and in a further embodiment, m is 2; and R² is an alkyl substitutedcarboxyl. In one embodiment, AR is phenyl. In another embodiment, R¹ istertiary octyl. The compound of formula I includes the embodiment whereR² is R³—C(═O)O—. A further embodiment of the compound of formula I iswhere m is 0, 1, or 2, and the compound is a dimer (bis), trimer (tris)or tetramer (ter), respectively, of the alkylphenyl naphthyl aminecoupled with formaldehyde.

The source of the R² group on the naphthyl ring is believed to be thepolyol ester reaction medium. As shown in Examples 3 and 4, when acoupling reaction utilizing formaldehyde is conducted in methanol orglacial acetic acid as an alternative to conducting the same reaction ina polyol ester base lubricant, as shown in Example 1, there is nocarbonyl absorbance in the Infrared spectrum in the products of eitherexamples 3 or 4. Accordingly, it is believed that the source of thecarbonyl absorbance in the compound of formula I when the compound isprepared using polyol ester as the reaction medium, is one of thecarboxylate moieties from the base polyol ester. If the formaldehydewere the source of the carbonyl, it could be expected that this reactionwould also occur where methanol or acetic acid was used as the solvent.In accord with the assumption that the source of the R² is thecarboxylate from the polyol ester, in one embodiment, R³ is selectedfrom the group consisting of linear or branched alkyl groups, i.e.,hydrocarbons C_(n)H_(2n+1) where n=4 to 11.

In the embodiment where the compound of formula I is formed in a baselubricant comprising acid esters of pentaerythritol, the organic acid ofR² is generally selected from the group consisting of valeric,isopentanoic, hexanoic, octanoic, isooctanoic, 2-ethylhexanoic,pelargonic, isononanoic, decanoic, and dodecanoic.

In example 1, where the pentaerythritol tetraester was formed fromstraight or branched chain C₅-C₁₀ with an average chain length of about6.3, R³ would likely be a similar distribution of straight or branchedchain C₄-C₉ alkyls. The R² carboxylate likely adds to the naphthyl ringby replacing a hydrogen atom at one or more of the 2, 4, 5, 7, and 8positions. In Example 1, the mole ratio of carboxyl oxygen (as O₂) to Nin the elemental analysis is about 0.85. This ratio suggests that thereis a significant degree of transfer of a carboxyl moiety from the polyolester to the nitrogen containing oligomer of formula I.

In a further aspect of the present invention, antioxidant additives aregenerally prepared by a condensation reaction of an alkylatedphenyl-α-naphthyl amine (ALK PANA) with formaldehyde in the presence ofa base lubricant. In one embodiment, a method of preparation includesmixing an alkylated phenyl-α-naphthyl amine, formaldehyde, glacialacetic acid, and a base lubricant, for example, a polyol ester. Thismixture is then heated and stirred to cause a condensation reaction.Water is generated and distilled off. Following the removal of thewater, the solution is heated and vacuum stripped to substantiallyremove residual water and acetic acid. The condensation product, namelyan antioxidant, remains in the base lubricant.

In one embodiment, the compound of Formula I is prepared by mixing analkylated phenyl-α-naphthyl amine, e.g.,N-4-alkylphenyl-1-naphthlyamine, paraformaldehyde, glacial acetic acidand a polyol ester base lubricant. In one embodiment, the polyol isselected from the group consisting of neopentyl glycol,trimethylpropane, pentaerythritol, dipentaerythritol, and the like. Inanother embodiment, the polyol is esterified with an organic acidselected from the group consisting of valeric, isopentanoic, hexanoic,heptanoic, octanoic, isooctanoic, 2-ethylhexanoic, pelargonic,isononanoic, decanoic, and combinations thereof. During manufacturing, ahydrocarbon can be added to form an azeotrope to ease in evolving thewater of reaction. In one embodiment, the hydrocarbon is one ofsaturated or aromatic hydrocarbons known to form azeotropes with water.

In another embodiment, the present invention includes a method forcompounding a lubricating oil or hydraulic fluid formulation thatincludes an antioxidant additive. The method includes providing alubricating oil or hydraulic fluid; and blending a sufficient quantityof a compatible base polyol ester lubricant having an antioxidant, forexample, the compound of formula I, prepared therein, so that theantioxidant achieves a preselected concentration. In a furtherembodiment, the lubricating oil is a polyol ester. In one embodiment,the resultant lubricating oil formulation substantially comprises apolyol ester. By reference to “substantially comprises a polyol ester”it is meant that the polyol ester comprises approximately at least about90% or more by weight of the final formulation.

By reference to lubricant or hydraulic fluid formulation, one skilled inthe art will recognize that this term encompasses a commercialformulation packaged for distribution in cans, drums or bulk containers.These lubricant formulations may include mineral oil based materials,synthetic lubricants, such as polyol esters, and compatible combinationsthereof. These formulations may also include one or more ofantioxidants, i.e., a compound of formula I, either solely or incombination with other compatible compounds, such as corrosioninhibitors, anti-wear agents, dispersants, metal passivants, and thelike. Useful concentrations of the compound of formula I in thelubricant or hydraulic fluid formulation are generally between about 0.1to about 10%. In one embodiment, a concentration for esterifiedpentaerythritol based formulations containing the compound of formula Iis between about 1.5 to about 5.5 percent by weight. Otherconcentrations of the compound of formula I in lubricants or hydraulicfluids may be envisioned for particular applications and are to beconsidered within the scope of the present disclosure.

EXAMPLE 1 Preparation of Compound of Formula I

N-(4-t-octylphenyl)-1-naphthylamine (161.4 g/0.487 mole) was mixed withparaformaldehyde (95%) (10.78 g/0.341 mole); glacial acetic acid (21.15g/0.352 mole); cyclohexane (50 g) and pentaerythritol tetraester (161.4g) containing mixed C₅-C₁₀ carboxylates (with an average carbon chainlength of about 6.3). The mixture was stirred and heated under a gentlenitrogen sparge to about 110° C. for about 90 minutes with thecyclohexane being distilled off as a water azeotrope into a Dean-Starktrap removing both water evolved and glacial acetic acid.

The aqueous acetic acid collected in the trap weighed 13.37 g andcontained 4.83 g of acetic acid (determined by titration). The remaining8.54 g includes the 6.14 g of water calculated for complete reaction aswell as the water present in the paraformaldehyde and the glacial aceticacid reactants.

Next, the reaction mixed was vacuum stripped by heating to 140° C. undervacuum (to about 1 mm Hg) for 2 hours. Following the vacuum stripping,the reaction mixture was treated with a nitrogen sparge (about 10 L/Hr)for about one hour. The resultant viscous reddish liquid weighed 323.4 gwith an acid no. of 0.07.

In order to further characterize the product from the above reaction, analiquot of the viscous reddish liquid was triturated two times withaliquots of methyl alcohol with vigorous mixing. The resultantprecipitate was then collected by vacuum filtration and further washedwith several more aliquots of methanol. The resultant pink powder wasdried under vacuum at 25° C. to constant weight providing a 45.7% yield(by weight) based on the reddish liquid. It is believed that the balanceof the reddish liquid comprised lower molecular weight species with somedegree of solubility in methanol. Infrared spectrum of the pink powdershows a carbonyl absorption at 1744 cm⁻¹, indicative of the presence ofan ester carbonyl. Further, the elemental analysis found for thisproduct, viz., C, 82.70; H, 8.88; N, 3.22; O, 6.24, shows a mole ratioof carboxyl oxygens to nitrogen of 0.85. These facts support theoccurrence of a significant degree of transfer of a carboxyl moiety fromthe polyol ester to the nitrogen-containing oligomer via a substitutionreaction.

Since the ALK PANA/formaldehyde mole ratio of reactants initiallycharged was 1.00/0.70, an average composition represented by a 3.33/2.33mole ratio of ALK PANA/formaldehyde oligomer should theoreticallyresult. By taking into account the contribution of the carboxylatemoiety, assuming an average C₅H₁₁C(═O)O— group, a molecular weight ofabout 1455 is calculated for the methanol-insoluble material asrepresented by an average formula of C_(99.23)H_(124.88)N_(3.33)O_(5.66)which provides a calculated elemental analysis of C, 81.92; H, 8.65; N,3.20; O, 6.22 comparing favorably with the “found” values state above.

GPC analysis of the isolated product was carried out in tetrahydrofuransolution and examined using a series of mixed pore size GPC columns.Detection of eluates was done using a photodiode array UV detector(Waters/Alliance 2996) with molecular weight calibration usingpolystyrene standards. The GPC values of M_(n)=1293, M_(w)=1558, whereD=1.20.

EXAMPLE 2 Condensation of N-Phenyl-1-Naphthylamine with Formaldehyde inPolyol Ester Solvent

Following the procedure of Example 1, N-phenyl-1-naphthylamine (150.3g/0.685 mole) was mixed with paraformaldehyde (95%) (15.2 g/0.481 mole),glacial acetic acid (31.1 g/0.518 mole), 62 g cyclohexane andpentaerythritol tetraester containing mixed C₅-C₁₀ carboxylates. Themixture was stirred with heating and then vacuum stripped. The resultantproduct was a viscous liquid weighing 321.0 g with an acid number of0.07. The methanol-insoluble component of this preparation was isolatedas a beige powder providing a yield by weight of 35.3%. The infraredspectrum of the isolated product also showed an absorbance at 1744 cm⁻¹,characteristic of carbonyl oxygen. Elemental analysis found for thisproduct, viz., C, 82.74; H, 6.74; N, 4.69, O, 6.44 indicates a moleratio of carboxyl oxygens to nitrogen as 0.60. Proceeding similarly toExample 1, a molecular weight of ca. 987 is calculated for thismethanol-insoluble material as represented by an average formula ofC_(67.67)H_(63.33)N_(3.33)O_(6.48). GPC data showed values of M_(n)=965,M_(w)=1076 where D=1.12.

EXAMPLE 3 Condensation of N-(4-t-octyl-1-naphthylamine) withFormaldehyde in Methanol

Following the procedure listed in U.S. Pat. No. 5,160,647, Example 1,N-(4-t-octylphenyl)-1-naphthylamine (33.1 g/0.1 mole) suspended inmethanol (150 ml) acidified with 98% H₂SO₄ (10.2 g/ca. 0.1 mole) wasmixed with 37.6% aqueous formaldehyde (4.0 g/0.05 mole) and heated toreflux for about 2 hours. After an extended workup as described in thereferenced patent, a beige product was obtained in 76.8% yield(calculated as the dimer) for which no carbonyl absorption in theInfrared spectrum was present. Analysis calculated for the dimerC₄₉H₅₈N₂, C, 87.19; H, 8.66; N, 4.15. Found C, 87.26; H, 8.61; and N,4.07. GPC analysis showed Mn=996, Mw=1076 and a D=1.08, which indicatesmostly a dimethylene-tris ALK PANA composition.

EXAMPLE 4 Condensation of N-(4-t-octyl-1-naphthylamine) withFormaldehyde in Glacial Acetic Acid

These examples (A-C) illustrate preparations using several mole ratiosof the nitrogen containing naphthylamine to formaldehyde.

-   -   A) mole ratio 1.0/0.5 (amine/formaldehyde).        N-(4-t-octylphenyl)-1-naphthylamine (22.97 g/0.0693 mole) was        mixed with stirring into 45 g of glacial acetic acid. This        mixture was heated to 65° C. with stirring to dissolve the        amine. 95% paraformaldehyde (1.09 g/0.0345 mole) was added and        rapidly dissolved. A precipitate, accompanied by an exotherm to        75° C., developed in less than one minute. The reaction mixture        was allowed to cool to room temperature and the insoluble        precipitate was collected, triturated with methanol in a Waring        Blendor®, suction filtered, washed with methanol and dried to        constant weight at 80° C. 15.83 g of a beige powder was        collected representing a 67.6% yield based on the weight of the        reactants. Analysis calculated for C₄₉H₅₈N₂; Calculated—C,        86.94; H, 8.62; N, 4.16; and Found—C, 87.19; H, 8.66; N, 4.15.        GPC analysis showed M_(n) of 918, a M_(w) of 1009 and a D value        of 1.10. The GPC result is substantially the same as that        obtained with the product of Example 3. No carbonyl absorbance        is present in the infrared spectrum.    -   B) mole ratio 1.0/0.67 (amine/formaldehyde).        N-(4-t-octylphenyl)-1-naphthylamine (22.97 g/0.0693 mole) was        mixed with stirring into 45 g of glacial acetic acid. This        mixture was heated to 65° C. with stirring to dissolve the        amine. 95% paraformaldehyde (1.53 g/0.0483 mole) was added and        rapidly dissolved. A precipitate, accompanied by an exotherm to        75° C., developed in less than one minute. The reaction mixture        was allowed to cool to room temperature and the insoluble        precipitate was collected, triturated with methanol in a Waring        Blendor®, suction filtered, washed with methanol and dried to        constant weight at 80° C. 18.99 g of a beige powder was        collected representing an 81.1% yield based on the weight of the        reactants. Analysis calculated for C₇₇H₈₇N₃; Calculated—C,        87.69; H, 8.32; N, 3.99; and Found—C, 87.10; H, 8.53; N, 4.00.        GPC analysis showed M_(n) of 1067, a M_(w) of 1334 and a D value        of 1.25. No carbonyl absorbance is present in the infrared        spectrum.    -   C) mole ratio 1.0/1.0 (amine/formaldehyde).        N-(4-t-octylphenyl)-1-naphthylamine (22.97 g/0.0693 mole) was        mixed with stirring into 45 g of glacial acetic acid. This        mixture was heated to 65° C. with stirring to dissolve the        amine. 95% paraformaldehyde (2.18 g/0.690 mole) was added and        rapidly dissolved. A precipitate, accompanied by an exotherm to        75° C., developed in less than one minute. The reaction mixture        was allowed to cool to room temperature and the insoluble        precipitate was collected, triturated with methanol in a Waring        Blendor®, suction filtered, washed with methanol and dried to        constant weight at 80° C. 21.4 g of a beige powder was collected        representing a 91.5% yield base on the weight of the reactants.        Analysis calculated for C₂₅H₂₉N, (repeating unit); Calculated—C,        87.40; H, 8.52; N, 4.08; and Found—C, 86.94; H, 8.47; N, 3.98.        GPC analysis showed M_(n) of 1565, a M_(w) of 2548 and a D value        of 1.63. No carbonyl absorbance is present in the infrared        spectrum.

Examples 4B) and C) substantially confirm, in accordance with acondensation oligomerization system, the expected formation of productsof higher average molecular weights together with a greaterdistribution, i.e., a higher D value, of products comprising theseaverages.

EXAMPLE 5 High Temperature Stabilization of Lubricating Oil

Aliquots of the compounds prepared in Examples 1, 2, 3, and 4 were usedto make industrial lubricant formulations having a composition of 95.29weight % ester, 2.35 weight % other additives, and variable weight % ofthe compounds of examples 1, 2, 3, and 4 as listed in Table 1 below.Oxidation Corrosion (OCS) testing was carried out using Federal TestMethod 5308 under conditions of 400° C., 72 hours, 5 liters/hour airflow using test metals of copper, aluminum, steel, silver, and zinc.Table 1 also lists: increase in viscosity; the acid number; the sludgegenerated; and the corrosion in mg/cm² in accordance with the standardtest for the several metals with the examples at several concentrationsin a polyol ester lubricant. A standard commercial lubricant (Vanlube9317) and an aliquot of the same polyol ester without any additivepackage are respectively used as a positive and a negative control. Theunbracketed values, e.g., “37.8” for Zn in the Negative control,indicate weight loss while the bracketed values, e.g., “(0.062)” for Cuin the Negative control, indicate weight gain.

TABLE 1 Conc. % Visc. % Acid Sludge Cu Al St Zn Ag Ex. # added. increaseNo. (mg.) mg/cm mg/cm mg/cm mg/cm mg/cm Neg. None 139.9 7.74 37.0(0.062) (0.023) (0.023) 37.8 (0.101) control 1 2.12 9.44 0.60 0.50 0(0.008) (0.039) 0.016 0.039 1 2.35 10.85 0.46 0.50 (0.008) (0.008)(0.008) 0.016 0.008 2 1.42 6.95 0 48.9 (0.194) (0.046) (0.046) (0.023)(0.039) 2 2.35 7.53 0.54 246 (0.029) (0.023) (0.047) (0.031) (0.093) 32.10 5.33 1.00 7.7 (0.008) 0.008 (0.023) (0.023) 0.054 4A 2.10 6.24 0.552.8 0.008 (0.008) (0.008) 0 0 4B 2.10 7.27 0.67 9.0 (0.008) 0.008 0.0080.016 0.023 4C 2.10 5.65 0.64 1.7 (0.016) (0.023) (0.062) (0.062)(0.062) Pos. 2.35 6.18 0.02 1.3 0.046 (0.008) (0.016) 0.016 0 control

The results for example 1 for formula I of the invention comparefavorably to the results of a current commercial standard (Vanlube 9317)given above as “Pos. control” determined under similar conditions.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present invention without departing from the spirit andscope of the invention. Thus, it is intended that the present inventioninclude modifications and variations that are within the scope of theappended claims and their equivalents.

1. A compound of formula

wherein R¹ is t-octyl; AR is phenyl; m is 0, 1, or 2; and R² is an alkylsubstituted carboxyl.
 2. The compound of claim 1 wherein m=0.
 3. Thecompound of claim 1 wherein m=1.
 4. The compound of claim 1 wherein m=2.5. The compound of claim 1 wherein R² is R³—C(═O)O—.
 6. The compound ofclaim 5 wherein R³ is selected from the group consisting of linear orbranched alkyl groups.
 7. The compound of claim 6 wherein the linear orbranched alkyl comprises C_(n)H₂₊₁ wherein n is from 4 to
 11. 8. Thecompound of claim 6 wherein the linear or branched alkyl group isderived from an organic acid ester of pentaerythritol, the organic acidbeing selected from the group consisting of valeric, isopentanoic,hexanoic, octanoic, isooctanoic, 2-ethylhexanoic, pelargonic,isononanoic, decanoic, dodecanoic, and combinations thereof.
 9. Thecompound of claim 7 wherein R³ is isobutyl.
 10. A lubricant or hydraulicfluid composition comprising an admixture of: from about 1.5 to about 5%(w/w) of a compound of formula I; up to about 5% of an additive packageselected from the group consisting of corrosion inhibitors, anti-wearagents, dispersants, metal passivants, and combinations thereof; and thebalance being a base material selected from the group consisting ofmineral oil based materials, synthetic lubricants, polyol esters, andcombinations thereof.
 11. The lubricant or hydraulic fluid compositionof claim 10, wherein the base material selected is a polyol ester isformed from a polyol selected from the group consisting of neopentylglycol, trimethylolpropane, pentaerythritol and dipentaerythritol; thepolyol being esterified with an organic acid selected from the groupconsisting of valeric, isopentanoic, hexanoic, heptanoic, octanoic,isooctanoic, 2-ethylhexanoic, pelargonic, isononanoic, decanoic,dodecanoic and combinations thereof.
 12. The lubricant or hydraulicfluid of claim 11 wherein the polyol is pentaerythritol, the polyolbeing esterified with an acid selected from the group consisting ofvaleric, isopentanoic, hexanoic, octanoic, isooctanoic, 2-ethylhexanoic,pelargonic, isononanoic, decanoic, dodecanoic and combinations thereof.13. The lubricant or hydraulic fluid of claim 12 wherein thepentaerythritol is esterified with C₅-C₁₀ straight chain or branchedacids having an average carbon chain length of about 6.3.
 14. Thelubricant or hydraulic fluid of claim 10 having a viscosity increase ofabout ten percent or less after testing according to Federal Test Method5308.
 15. The lubricant or hydraulic fluid of claim 10 having an acidnumber increase of no more than about one after testing according toFederal Test Method
 5308. 16. A method of lubricating an apparatusselected from the group consisting of a stationary turbine, a jetengine, and a hydraulic system, the method comprising: providing a fluidmaterial comprising an admixture between about 0.1 and 10% (w/w) of acompound of formula I, an additive package selected from the groupconsisting of corrosion inhibitors, anti-wear agents, dispersants, metalpassivants, and combinations thereof, the balance being a base materialselected from the group consisting of mineral oil based materials,synthetic lubricants, polyol esters, and combinations thereof; andplacing the fluid material in the system.
 17. The method of claim 16,wherein the providing step further comprises selecting a polyol esterbase lubricant formed from a polyol selected from the group consistingof neopentyl glycol, trimethylolpropane, pentaerythritol, anddipentaerythritol; the polyol being esterified with an organic acidselected from the group consisting of valeric, isopentanoic, hexanoic,heptanoic, octanoic, isooctanoic, 2-ethylhexanoic, pelargonic,isononanoic, decanoic, dodecanoic, and combinations thereof.
 18. Themethod of claim 17 wherein the providing step comprises selecting apolyol ester base lubricant formed from pentaerythritol and C₅-C₁₀straight chain or branched acids having an average carbon chain lengthof about 6.3.
 19. A packaged commercial lubricant or hydraulic fluidcomposition for distribution comprising: between about 0.1 and 10% (w/w)of a compound of formula I; an additive package selected from the groupconsisting of corrosion inhibitors, anti-wear agents, dispersants, metalpassivants, and combinations thereof and the balance being a basematerial selected from the group consisting of mineral oil basedmaterials, synthetic lubricants, polyol esters, and combinationsthereof; and a container selected from the group consisting of cans,drums or bulk containers.
 20. The packaged composition of claim 19,wherein the base material selected is a polyol ester is formed from apolyol selected from the group consisting of neopentyl glycol,trimethylolpropane, pentaerythritol and dipentaerythritol; the polyolbeing esterified with an organic acid selected from the group consistingof valeric, isopentanoic, hexanoic, heptanoic, octanoic, isooctanoic,2-ethylhexanoic, pelargonic, isononanoic, decanoic, dodecanoic andcombinations thereof.